Why Are Disease Outbreaks from Pork Products on the Rise?

Foodborne illness outbreaks are still uncommon, but they can be widespread and serious when they happen. Here are some safety tips.

The number of disease outbreaks linked to food in the United States has decreased overall in recent years.

But the percentage of those attributed to pork has risen.

A by the Centers for Disease Control and Prevention (CDC) found that from the period of 1998 to 2015, 288 outbreaks were linked to pork.

The frequency of outbreaks due to pork decreased by 37 percent during this time period, which was in line with a total decline of foodborne outbreaks.

However, in 2015 the number of pork-related outbreaks increased by 73 percent compared with the previous three years.

And it’s not just because we’re eating more bacon.

“Estimates of pork consumption show a slight increase in 2015, but not to the extent that pork-associated outbreaks increased. CDC and partners are monitoring outbreak reports to determine if this was an unusual year or the beginning of a new trend,” Julie Self, PhD, who works in the CDC’s Epidemic Intelligence Service, told Healthline.

What the numbers reveal

The 288 outbreaks attributed to pork between 1998 and 2015 resulted in 6,372 illnesses, 443 hospitalizations, and four deaths.

Salmonella was found to be the most common pathogen linked to pork outbreaks.

But it’s probably still safe to eat your ham sandwich for lunch.

According to Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center, the odds of contracting an illness due to pork remains low.

“Pork-related infections now are rare, considering the huge volume of pork consumed each year. Most are caused by salmonella, a bacterial infection that causes an intestinal illness characterized by fever and diarrhea. Salmonella can sometimes gain access to the bloodstream and cause sepsis — a serious, life-threatening infection,” Schaffner told Healthline.

Although the number of overall foodborne outbreaks is declining, Schaffner notes that when outbreaks do occur they have the potential to be serious.

“Because of the large-scale commercialization of our food supply, foodborne outbreaks now are less apt to be small or local and more likely to be larger and spread over a greater expanse geographically. Thus they are taken very seriously by public health and the food service industry,” he said.

It starts on the farm

Keeping food safe relies on a number factors working well every day.

In simple terms, foodborne diseases are the result of eating food contaminated with germs.

“Sometimes, the germs contaminate the animals or plants we eat while they are being raised, even before they are harvested. Sometimes, the contamination occurs during processing, such as during slaughter or packing, and sometimes it occurs in the kitchen during preparation. Most of the illnesses are caused by germs that spend most of their life in farm animals, usually without making them sick,” Dr. Rob Tauxe, director of the CDC’s Division of Foodborne, Waterborne, and Environmental Diseases, told Healthline.

“Preventing foodborne disease starts on the farm, with good agricultural practices for the raising and harvesting of the plants and animals we eat. It also depends on careful processing, and final preparation all along the way, from farm to table. Many people doing the right thing every day are key partners in making our food safe,” he said.

What to do in the kitchen

Following food safety practices in the kitchen is an essential component of eliminating the risk of food-related illness.

A found that only pork chops that were cooked until well done completely eliminated listeria and salmonella pathogens.

Pork cooked to rare or medium left a few surviving cells that could then multiply while the food is stored.

Undercooked pork also puts you at risk of other infections.

“Taenia solium cysticercosis, which is a pork tapeworm, can also occur. Taenia infection may occur through ingestion of undercooked pork, but can also occur through contamination through other humans. Say if someone has the infection and does not wash their hands after using the restroom and then goes to prepare food, they can contaminate the food they prepare,” Dr. Dana Hawkinson, infectious disease specialist at The University of Kansas Health System, told Healthline.

On the whole, however, commercially produced pork products should be quite safe to consume.

“Pork that comes from commercial farms is a very safe food. Years ago, there was more ‘backyard’ pork in local markets that came from pigs fed food scraps and garbage by individuals. That meat occasionally was the source of trichinosis, a parasitic infection, but I do not recall such a case in over 20 years now,” Schaffner said.

Antibiotic resistance a problem

While many salmonella infections resolve without medical treatment, serious cases can be deadly without antibiotics.

A found that 20 percent of blood isolates in salmonella bacteria are resistant to a first-line antibiotic treatment.

Antibiotic resistance represents a significant global health problem, and the use of antibiotics in agriculture is a hotly contested issue in the United States.

“Antibiotics are used in food animals for many reasons, such as treating ill animals, or preventing and controlling disease outbreaks. Antibiotics have also been used for growth promotion. We can’t combat the spread of antibiotic resistance without improving the prudent use of antibiotics in both humans and food animals,” Tauxe said.

The has approved antibiotic use in food animals for disease treatment of sick animals, disease control for groups of animals, and disease prevention among animals.

But use of antibiotics for other reasons in farming continues to generate debate.

“The issue of the overuse of antibiotics as growth promoters in raising farm animals for food continues to be a contentious matter in the U.S. The Europeans have been more restrictive than we in the U.S. We in infectious disease practice would very much like to see less use of antibiotics in food production because it contributes to the development of antibiotic-resistant bacteria, making it more difficult to treat infections when they occur,” Schaffner said.

“It is a tough problem politically because the commercial food producers object to further restrictions. You have to get involved at the local level, letting Congress members and senators know how you feel,” he added.